package cn.springboot.hadoop;

import java.io.IOException;
import java.util.StringTokenizer;

import org.apache.hadoop.conf.Configuration;
import org.apache.hadoop.fs.Path;
import org.apache.hadoop.io.IntWritable;
import org.apache.hadoop.io.Text;
import org.apache.hadoop.mapreduce.Job;
import org.apache.hadoop.mapreduce.Mapper;
import org.apache.hadoop.mapreduce.Reducer;
import org.apache.hadoop.mapreduce.lib.input.FileInputFormat;
import org.apache.hadoop.mapreduce.lib.output.FileOutputFormat;

import cn.springboot.config.SysConfig;

/**
 * @author liufl E-mail:Huberier@allpyra.com
 * @version 创建时间：2017年9月27日 上午9:36:32 类说明
 * 不拆词统计-出现次数
 */
public class HDFSWordCount {
	public static class TokenizerMapper extends Mapper<Object, Text, Text, IntWritable> {

		private final static IntWritable one = new IntWritable(1);
		private Text word = new Text();

		public void map(Object key, Text value, Context context)
				throws IOException, InterruptedException {
			StringTokenizer itr = new StringTokenizer(value.toString());
			while (itr.hasMoreTokens()) {
				word.set(itr.nextToken());
				context.write(word, one);
			}
		}
	}

	public static class IntSumReducer extends
			Reducer<Text, IntWritable, Text, IntWritable> {
		private IntWritable result = new IntWritable();

		public void reduce(Text key, Iterable<IntWritable> values,
				Context context) throws IOException, InterruptedException {
			int sum = 0;
			for (IntWritable val : values) {
				sum += val.get();
			}
			result.set(sum);
			context.write(key, result);
		}
	}

	public static void main(String[] args) throws Exception {
		Configuration conf = new Configuration();
        conf.addResource("classpath:/hadoop/core-site.xml");  
        conf.addResource("classpath:/hadoop/hdfs-site.xml");  
        conf.addResource("classpath:/hadoop/mapred-site.xml");  
		Job job = Job.getInstance(conf, "word count");
		job.setJarByClass(HDFSWordCount.class);
		job.setMapperClass(TokenizerMapper.class);
		job.setCombinerClass(IntSumReducer.class);
		job.setReducerClass(IntSumReducer.class);
		job.setOutputKeyClass(Text.class);
		job.setOutputValueClass(IntWritable.class);
		FileInputFormat.addInputPath(job, new Path(SysConfig.HDFSURL+"/tmp/input"));//必须存在
		FileOutputFormat.setOutputPath(job, new Path(SysConfig.HDFSURL+"/tmp/output2"));//必须不存在
		System.exit(job.waitForCompletion(true) ? 0 : 1);
	}
}
